Oklahoma Milkweed Species to Include in your Butterfly Garden
There are twenty-six species of native Oklahoma milkweeds (Asclepias spp.) that can be grown for Monarch Butterflies and other insects. Milkweeds are an important host species for Monarch, Queen, and Soldier Butterflies. The Monarch butterfly in particular uses the cardenolides found in the milky sap of milkweeds to give an unpleasant taste to predators. These plants are also an important nectar source to all insects visiting your pollinator garden.
Oklahoma Milkweeds
1. Clasping Milkweed (Asclepias amplexicaulis), a Milkweed for Dry Soils
Clasping Milkweed (Asclepias amplexicaulis): Clasping milkweed is native in the central and eastern counties of Oklahoma (Kartesz 2015). In the wild, Clasping milkweed grows in dry woodlands, prairies, meadows, and roadsides having sandy or gravelly soil. Growing up to 3 feet tall, this plant has greenish-pink, red, brown, to purple flowers that bloom from March to September.
In your Oklahoma butterfly garden, clasping milkweed is hardy in zones 3-9 and can be grown in places with full sun to part-shade having dry sandy soil. Seeds of clasping milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
2. Western Sand Milkweed (Asclepias arenaria), a Milkweed for Sandy Soil
Western Sand Milkweed (Ascelpias arenaria): Western sand milkweed is native mainly in the central and western counties of Oklahoma (Kartesz 2015). In the wild, western sand milkweed grows in open places such as fields, pastures, dunes, sandhills, and roadsides. This milkweed grows up to 3 feet tall, and has pale-green to greenish-white flowers having a purplish hue that bloom from May to October.
In your Oklahoma butterfly garden, western sand milkweed requires sandy well-drained soil in full sun and is hardy in zones 4-9. Seeds of western sand milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
3. Spider Milkweed (Asclepias asperula), a Milkweed for Dry Soils
Spider Milkweed (Ascelpias asperula): Spider milkweed is native throughout Oklahoma, except for the eastern counties (Kartesz 2015). Spider milkweed has two subspecies, one of which, subspecies capricornu is in Oklahoma. In the wild, spider milkweed is found in dry open habitats such as desert swales and scrub and pastures. Growing from 1 to 3 feet high, the cream-green flowers bloom from April to June.
In your Oklahoma butterfly garden, spider milkweed requires a full sun exposure with dry and/or rocky soils. Seeds of spider milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
4. Engelmann’s Milkweed (Asclepias engelmanniana), a Milkweed for Dry Soils
Engelmann’s Milkweed (Ascelpias engelmanniana): Engelmann’s milkweed is native to throughout Oklahoma except for a scattered distribution in the eastern counties (Kartesz 2015). In the wild, Engelmann’s milkweed is found in dry open habitats such as desert swales, scrub and pastures. Growing from 2 to 5 feet tall, this plant has cream-green flowers that bloom from May to September.
In your Oklahoma butterfly garden, Engelmann’s milkweed requires full sun, dry sandy or limestone soils and is hardy in zones 5-9. Seeds of Engelmann’s milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
5. Swamp Milkweed (Asclepias incarnata), a Milkweed for Moist Soils
Swamp Milkweed (Asclepias incarnata): Swamp milkweed has two subspecies, ssp. incarnata and ssp. pulchra. The former is native in the mainly in the eastern counties of Oklahoma (Kartesz 2015), while the latter is not present. Like the name suggests in the wild it is found in wet places including the shores of streams, lakes, ponds, and other wetlands. This is one of the taller milkweeds growing from 3 to 5 feet tall. The flowers, which bloom from July to September are generally a pink to red color, but there is also a white cultivar (pictured below).
In your Oklahoma butterfly garden, var. incarnata of swamp milkweed is hardy in zones 3-9 and requires full sun to part shade and prefers moist to medium moisture soil, but it can exist in drier soil. Seeds of swamp milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
6. Dwarf Milkweed (Asclepias involucrata), a Milkweed for Sandy Well-drained Soils
Dwarf Milkweed (Asclepias involucrata): Dwarf milkweed is native and rare in Cimarron County in the western panhandle of Oklahoma (Kartesz 2015). In the wild, this species grows on prairies with sandy soil. This is one of the shorter milkweeds growing from 0.5 to 1 foot tall. The flowers, which bloom from May to June are white to green (Singhurst and Hutchins 2015).
In your Oklahoma butterfly garden, dwarf milkweed requires full sun and well-drained sandy soil. However, this species is rare in a lot of its range and is likely not in the horticultural trade.
7. Side-Cluster Milkweed (Asclepias lanuginosa), an Oklahoma Milkweed for Moist to Wet Soils
Side-Cluster Milkweed (Asclepias lanunginosa): Side-cluster milkweed is native and rare in Woods County in the northern part of Oklahoma. (Kartesz 2015). In the wild, side-cluster milkweed grows on prairies and sandhills having full sun. The height of this milkweed is variable and ranges from 0.5 to 4 feet tall, but can grow up 6 feet in favorable places. The flowers range in color from green to cream and bloom from May to July.
While side-cluster milkweed is hardy in zones 4-7 it is rare and not in the horticultural trade.
8. Broad-leaf Milkweed (Asclepias latifolia), a Milkweed for Dry Sandy Soils
Broad-leaf Milkweed (Asclepias latifolia): Broad-leaf milkweed is native in the central and western counties of Oklahoma (Kartesz 2015). In the wild, broad-leaf milkweed grows in open areas having full sun such as prairies, roadsides, and other right-of-ways. Growing from 1 to 3 feet tall, the greenish to yellow flowers bloom from May to August.
In your Oklahoma butterfly garden, broad-leaf milkweed is hardy in zones 5-8, and grows best in places having full sun to part-shade with dry sandy soils. Seeds of broad-leaf milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
9. Long-leaf Milkweed (Asclepias longifolia), a Milkweed for Moist Soils
Long-leaf Milkweed (Asclepias longifolia): Long-leaf milkweed is native generally in the eastern and central counties of Oklahoma (Kartesz 2015). This species has two varieties, var. hirtella and var. longifolia, both of which occur in the state. The former is more common in the central and eastern counties, while the latter is rarer and more scattered in distribution. In the wild, long-leaf milkweed grows in moist areas and wetlands such as bogs, swamps, wet flatwoods, and moist prairies. Growing from 1 to 2.5 feet tall, the greenish-white flowers bloom from April to July.
In your Oklahoma butterfly garden, long-leaf milkweed requires full sun, moist to wet soils, and is hardy in zones 4-9.
10. Long-hood Milkweed (Asclepias macrotis), a Milkweed for Dry Soils
Long-hood Milkweed (Asclepias macrotis): Long-hood milkweed is native and rare in Cimarron and Texas Counties in the western panhandle of Oklahoma (Kartesz 2015). In the wild, long-hood milkweed grows on dry hills and mesas (Woodson 1954) and limestone (Singhurst and Hutchins 2015) having full sun. Growing from 0.3 to 1 foot tall it is among the shortest milkweeds in Texas. The greenish-yellow to yellowish-white flowers bloom from May to October.
In your Oklahoma butterfly garden, long-hood milkweed is hardy in zones 8-10 and requires full sun with dry soils.
11. Pineland Milkweed (Asclepias obovata), a Milkweed for Well-drained Soils in Full Sun
Pineland Milkweed (Asclepias obovata): Pineland is native to the southeastern counties of Oklahoma (Kartesz 2015). In the wild, pineland milkweed grows, as the name would suggest, on pinelands, but it also can be found on coastal prairies (Singhurst and Hutchins 2015) and on roadsides and fields. Growing from 0.5 to 3 feet tall, this species has greenish-yellow flowers with purplish hoods that bloom from June to October.
In your Oklahoma butterfly garden, pineland milkweed is hardy in zones 7-10 and requires full sun with well-drained soils.
12. Zizotes Milkweed (Asclepias oenotheroides), a Milkweed for Well-drained high pH Soils
Zizotes Milkweed (Asclepias oenotheroides): Zizotes milkweed is native with a scattered distribution in the central and southern counties of Oklahoma (Kartesz 2015). In the wild, zizotes milkweed grows on rocky areas with limestone having a high pH. It can also be found in open areas such as fields, thickets, and roadsides (Woodson 1954). Growing from 1 to 2 feet tall, this species has white, greenish-white to yellow flowers that bloom from April to November.
In your Oklahoma butterfly garden, zizotes milkweed is hardy in zones 7-9 and requires full sun to partial-shade with mesic to dry well-drained high pH soils.
13. Low Milkweed (Asclepias pumila), a Milkweed for Dry Soils
Low Milkweed (Asclepias pumila): Low milkweed is native to the central and western counties of the state (Kartesz 2015). In the wild, low milkweed grows in dry open areas having full sun such as prairies. One of the shorter milkweeds, this plant grows from 0.5 to 1.5 feet tall. The flowers are white, greenish-white or yellowish-white with hints of red and bloom from July to September.
In your Oklahoma butterfly garden, low milkweed requires full sun, dry sandy and/or gravelly soils, and is hardy in zones 5-9.
14. Purple Milkweed (Asclepias purpurascens), a Milkweed for Moist Soils
Purple Milkweed (Asclepias purpurascens): Purple milkweed is native and scattered in four eastern counties in Oklahoma (Kartesz 2015). In the wild, purple milkweed grows in moist to dry places having full sun to part shade such as swamps, woodlands, meadows, roadsides, and dry fields. Growing up to 6 feet tall, this plant has purple to pink flowers that bloom from May to July.
In your Oklahoma butterfly garden, purple milkweed is hardy in zones 3-8 and requires part shade but can handle full sun. Soils should be moist and well-drained, but dry soil can be tolerated. Seeds of purple milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
15. Four-leaf Milkweed (Asclepias quadrifolia), a Milkweed for Dry/Rocky Soils
Four-leaf Milkweed (Asclepias quadrifolia): Four-leaf milkweed is native mainly in the eastern counties and one county in the central part of Oklahoma (Kartesz 2015). In the wild, four-leaf milkweed grows in open areas such as roadsides, pastures, and prairies that are dry or rocky. Growing from 1 to 3 feet tall, this milkweed has white to pink flowers that bloom from April to July.
In your Oklahoma butterfly garden, four-leaf milkweed is hardy in zones 5-8 and requires full sun to part shade and dry/rocky soils.
16. Showy Milkweed (Asclepias speciosa), a Milkweed for Medium to Dry Soils
Showy Milkweed (Asclepias speciosa): Showy milkweed is native and has a scattered distribution throughout Oklahoma (Kartesz 2015). In the wild, showy milkweed grows in mesic to dry open areas such as roadsides, fields, and woodlands. Growing from 1 to 3 feet tall, this plant has purple to pink flowers that bloom from April to June.
In your Oklahoma butterfly garden, showy milkweed is hardy in zones 3-9 and requires places of full sun having medium to dry well-drained soil. Seeds of showy milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
17. Slim-leaf Milkweed (Asclepias stenophylla), a Milkweed for Dry Soils
Slim-leaf Milkweed (Asclepias stenophylla): Slim-leaf milkweed is native throughout Oklahoma (Kartesz 2015). In the wild, slim-leaf milkweed grows in open areas with full sun such as prairies and sandy areas. Growing from 0.5 to 3 feet tall, this milkweed has greenish-white flowers that bloom from June to August.
In your Oklahoma butterfly garden, slim-leaf milkweed is hardy in zones 3-9 and requires full sun and dry sandy or gravelly soils. Seeds of slim-leaf milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
18. Horsetail Milkweed (Asclepias subverticillata), a Milkweed for All Soils
Horsetail Milkweed (Asclepias subverticillata): Horsetail milkweed is native in two counties, Cimarron and Alfalfa in Oklahoma (Kartesz 2015). In the wild, horsetail milkweed grows in open areas with full sun such as rocky plains and flats, roadsides, waste places, and marshes and wet areas. Growing up to 4 feet tall, this milkweed has white to greenish-white flowers that bloom from May to September.
In your Oklahoma butterfly garden, horsetail milkweed is hardy in zones 5-8, requires full sun, and can handle a variety of moisture conditions. Seeds of horsetail milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
19. Sullivant’s Milkweed (Asclepias sullivantii), a Milkweed for Medium to Dry Soils
Sullivant’s Milkweed (Asclepias sullivantii): Sullivant’s milkweed is native with a very scattered distribution eastern and central counties of Oklahoma (Kartesz 2015). In the wild, Sullivant’s milkweed grows in open areas with full sun such as prairies, meadows, roadsides, and railroads. Growing from 2 to 5 feet tall, this milkweed has pink to purplish flowers that bloom from June to July.
In your Oklahoma butterfly garden, Sullivant’s milkweed is hardy in zones 3-7 and requires full sun and medium to dry sandy soil. Seeds of Sullivant’s milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
20. Common Milkweed (Asclepias syriaca), a Milkweed for All Soils
Common Milkweed (Asclepias syriaca): Common milkweed is native throughout Oklahoma, but with a scattered distribution (Kartesz 2015). In the wild, common milkweed grows in open areas such as fields, pastures, and roadsides, where there is full sun. One of the taller milkweeds, it can grow up to 6 feet tall and has flowers ranging from pink, greenish-purple, greenish-white, to white that bloom from June to August.
In your Oklahoma butterfly garden, common milkweed is hardy in zones 3-9. Seeds of common milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
21. Butterfly Weed (Asclepias tuberosa), a Milkweed for all Soils
Butterfly Weed (Asclepias tuberosa): Butterfly weed is one of the most common for butterfly gardeners on the east coast of the United States. In Oklahoma, subspecies interior of this species grows throughout Oklahoma (Kartesz 2015). In the wild, butterfly weed grows in open areas with full sun such as fields, roadsides, and open woods. Growing from 1 to 3 feet tall, it has characteristically orange flowers that bloom throughout the summer and sometimes into the autumn.
In your Oklahoma butterfly garden, butterfly weed is hardy from zones 3-9. Seeds of butterfly weed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
22. Wheel Milkweed (Asclepias uncialis), a Milkweed for Well-drained Soil
Wheel Milkweed (Asclepias uncialis): Wheel milkweed is native and rare in Cimarron and Texas Counties in Oklahoma (Kartesz 2015). In the wild, wheel milkweed grows in open areas with full sun such as shortgrass prairie, sandstone rocks, and pinyon-pine woodlands. Growing from 1 to 2.5 inches tall, it is the shortest milkweed in Texas. In the spring (March to June), the rose-purple to pink flowers bloom. The flowers are noted for their fragrance (Decker 2006).
In your Oklahoma butterfly garden, wheel milkweed is hardy in zones 6-8. This species is rare in all of the states where it is found and is not in cultivation.
23. Red-Ring Milkweed (Asclepias variegata), a Milkweed for Dry Soils
Red-Ring Milkweed (Asclepias variegata): Red-ring milkweed is native to the eastern counties of Oklahoma (Kartesz 2015). In the wild, red-ring milkweed grows in thickets, open woods and roadsides that are dry and rocky/sandy. Growing from 1 to 4 feet tall, it has white flowers with a purple or red ring at the base that bloom from May to July.
In your Oklahoma butterfly garden, red-ring milkweed is hardy in zones 3-9. Seeds of red-ring milkweed can be purchased in the McMullen House Bed & Breakfast Garden Shop.
24. Whorled Milkweed (Asclepias verticillata), a Milkweed for Medium to Dry Soil
Whorled Milkweed (Asclepias verticillata): Whorled milkweed is native throughout Oklahoma (Kartesz 2015). Whorled milkweed has green to white flowers that bloom from May to September. In the wild, like a lot of other milkweeds, it grows in open areas such as meadows and fields, taking advantage of full sun.
In your Oklahoma butterfly garden, whorled milkweed is hardy in zones 3-9, requires full sun to part shade, and medium to dry soil. Seeds of whorled milkweed can be purchased at the McMullen House Bed & Breakfast Garden Shop.
25. Green Comet Milkweed (Asclepias viridiflora), a Milkweed for Medium to Dry Sandy Soils
Green Comet Milkweed (Asclepias viridiflora): Green comet milkweed is native throughout Oklahoma (Kartesz 2015). In the wild, it grows in open areas such as meadows and fields having full sun. Growing up to 3 feet tall, it has flowers that start out green and age to become yellow and purple tinged that bloom from June to August.
In your Oklahoma butterfly garden, green comet milkweed is hardy in zones 3-9, requires full sun to part shade, and medium to dry sandy soil. Seeds of green comet milkweed can be purchased at the McMullen House Bed & Breakfast Garden Shop.
26. Green Milkweed (Asclepias viridis), a Milkweed for Medium to Dry High pH Soils
Green Milkweed (Asclepias viridis): Green milkweed is native throughout Oklahoma, except for the western panhandle (Kartesz 2015). In the wild, green milkweed grows in open areas such as glades, prairies, roadsides, and pastures where there is full sun. Growing from 0.5 to 2 feet tall, it has green, yellowish-green, or white flowers that bloom from April to October.
In your Oklahoma butterfly garden, green milkweed is hardy in zones 5-9 and requires medium to dry soils having a high pH. Seeds of green milkweed can be purchased at the McMullen House Bed & Breakfast Garden Shop.
When selecting your Oklahoma milkweed, be sure to make sure it grows in your zone and habitat.
References for Oklahoma Milkweeds
- Decker, K. 2006. Asclepias uncialis Greene (wheel milkweed): a technical conservation assessment. US Forest Service, Rocky Mountain Region.
- Kartesz, J.T. The Biota of North America Program (BONAP). 2015. Taxonomic Data Center. Link to website. Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]
- Woodson, Robert E. 1954. The North American Species of Asclepias L. Annals of the Missouri Botanical Garden 41: 1-211.
